You can use Lazarus: Form Recovery, a chrome extension.
Autosaves everything you type so you can easily recover from
form-killing timeouts, crashes and network errors.
Ever had one of
those “oh $*#@” moments when you've finally finished filling out a
long form, and hit submit only to see an error message? And when you
hit the back button, the form was blank... If so, you know you need
Lazarus. And if not, you have a chance to install Lazarus before
Lazarus saves everything you type so if the worst happens you can
recover the whole form by simply clicking a menu item. The data can be
encrypted and is saved on your machine so you know it's safe.
Similar extension is also available for firefox.